Strap stretching device



W. C. CHILDRESS STRAP STRETCHING DEVICE Feb. 18, 1936.

2 Sheets-Shea?l 1 Filed Oct. 17, 1935 ess @Si IIIIIIIIIIII 11| www Feb. 18, 1936. w. c; cHlLDREss 2,031,462

STRAP STRETCHING DEVICE Filed Oct. 17, 1935 2 Sheets-Sheet 2 QO-g 30 Patented Feb." 1,8, 1936 UNITED PATENT- orliosz v aoainsz STRAP s'rmi'rmino. nevica i William C.'Childress, 0ak Park, Ill., assigner ,tol Acme Steel Company, Chicago, Ill., a corporation of Illinois Application october .17, 1935, ,serial No. 45,493

13 Claims. (Cl. 254-66) This invention relates to improvements in strap stretching devices and its purpose is to providean.

improved devicefor use'indrawing metal binders` taut around-boxes, packages or groups of packages preliminary to fastening the overlapping ends thereof together. 'Ihe principal-object of th in-v vention is to provide an improved strap stretching device comprising gripping devices adapted to engage a flexible binder passed around a package 10 orthe like, such as a fiat flexible steel strap and including means for automatically effecting" the release of the gripping devices from the binder after it has been drawn taut. Another object of the invention is to provide an improved strap it stretching device comprising relatively movable gripping devices adapted to engage a flexible bind-'- er passed around a package or the like and comprising, operating mechanism for drawing the strap taut in combination with means adapted to 20 be actuated by said operating mechanism for re leasing one of said gripping devices `from the binder. Still another object of the invention is to provide an improved strap stretching device coinprising a gripping member normally actuated by 25 resilient means to engagea flexible binding strap.

or the like, in combination with other means adapted to be energized by the operating mechanism of the device for causing the gripping mem` ber to be released from the strap after the strap 30. has been drawn taut. Still another object of the invention is to provide an improved strap stretching device comprising relatively movable mem- `.bers each carrying a gripping device adapted to engage one end o a flexible binder or the like 35 drawn around a package in combination with operating mechanismvfor effecting relative move ment of said members to draw the strap taut and resilient means actuated by said operating mechanism lforoausing one of said gripping devicesto- 5o box or package and engaging a flexible binder- -which has been drawn taut around the box or package;

Y Fig-i2 shows a top plan view ci the structurev illustrated in Fig. 1;

Fig. 3`is a sectional view taken on the line 3-3 of Fig. 1;

Fig. 4 is a perspective view of the lower end of the operating lever of the strap stretching device, showing the cam which operates to actuate the 5 resilient means by. which one of the gripping def vices is released from the strap;

. Fig. 5 is a3' perspective view ofa pawl carried by the operating lever and of an adjacent" stationary l cam adapted to actuate4 the pawl to disengage it 10 from the ratchet wheel when the lever reaches a predetermined position; l

Fig. 6 is an enlarged horizontal section taken on the lines 6-6 of Figs. 1 and 8;

Fig. 7 is a vertical section taken on the line "i--l 15 of Fig. 6;

Fig. 8`is a longitudinal vertical section taken on the line t-B of Fig. 6 with the operating lever in 'the position shown in Fig. l, wherein the pawl engages the ratchet wheel; 20

Fig. 9 shows a side elevation of the right-hand portion of the strap stretching device illustrated in Fig, 1, with a partial vertical section on theA line @-3 of Fig. 6; and lEig. 10 shows an enlarged horizontal section 25 taken-cn the line ite-ill of Fig. 9. y f

As illustrated in the drawings, the improved strap stretching device ,l5 is shown as beingmounted on the top'surface of a box or package It about which there is passed a flat exible steel '30 y strap il which has been drawn taut preliminary to securing the overlapping ends Il and l'ib thereof together by means of a seal joint I 8. This joint may be of various forms but may preferably beof'ithe form disclosed in the .United States 35 patent of Ralph H. Norton No. 1,260,016, dated March 19,1918.

The sealing device AI5 comprises .a block 20 which rests upon the surface of the package I6 and which has a lon itudinal slot 2li lextending 40 therethrough to be c osely-itted by the endof a rack bar 2l. This rack bar is secured in rigid relation to `the block 20 by a cap screw 22 extending through the bar and the lower walls of the slot and'having a threaded engagement with 45 the lower wall, as shown in Fig. 3. The block 2.0 has a forwardly extending flange 2Gb adapted to be engaged on its upper side by the end portion" Ilav of the strap I1 and this .flange is beveled downwardl'toward the end of the package I6 50` to faciltiate' the passage of a strap thereover. The strapsA i1 is, held in engagement with the ange 2lih by a gripping dog 23 which is rotatably mounted upona pin 24 secured in an aperture' 20 formed in the block 20.. The pin 2,4 is heldin 55 piooe by e. vertically extending `pin 2s passing downwardly through the block 2 8 and through a groove formed in one side of the pin '24. The pin 24 is provided at its outer end with an enlarged head or flange 24` which overlies the hub portion 2 3* of a handle 2E, formed of bronze or the like, which-is engaged by the pin 24 and which has .a fixed relation to the gripping dog 23 through the coaction of its lower horizontal edge 2lb with the shoulder 23h formed on the gripping dog. 'I'he gripping dog is provided with a lower serrated gripping surface 23 whichv is adapted to engage and bite into the upper surface -of the strapY I1 and this gripping surface is odset toward the right from a plane passing through the axis of the pin 24, as viewed in Fig. 1, ao that apull upon. the strap I1 toward the left tends to increase the grip of the dog, upon the strap while relative movement of the strap and gripping dog in the opposite direction tends to.. release the strap. The gripping dog 23 is provided with a cylindrical bore'23d in which is mounted a pin or plunger 21- adapted tobe pressed against a ange 23l on the block 28 by a coil spring 23 which is mounted in the inner end of the The pin 21 and spring 28 thus tend nor- Vwith rack teeth 2l'l and this portion of the bar is slidably engaged by a hollowblock or housing. 3l having rectangular apertures 3I| and 3l" in` the end walls thereof which are slidably engaged by the rack bar, as sh'own Fig. 8. 'I'he block 33 is providedwith a forwardly extending flange 38 at its .lower edge which is adapted'to be engaged on its upper side by `the end portion I1b of the strap I1 and this flange is also beveled on its upper. side towardthe adjacent end of the pack- `age to facilitate the e of the strap thereover. The strap I1 is adapted to be held in engagementwith the ange 3I=` by a gripping dog -33 which is rotatably mounted upon a pin 34 secured in a bore 33d formed in' the block, as shown in Figf, and th`e pin 34-is adapted to be held in this position by a vertically extending pin- 35 passing downwardly through the.block"' and a groove formed in the lateral side of the pin 34.

This pin 34`hag an enlarged head 34* which over-l llies the -front face of the gripping dog 33.and the gripping dog is provided on its under side with a serrated gripping surface 33 which is adapted to engage and bite into the metal of the strap I1 on its upper side. Asviewed infFig. 1, the serrated gripping surface 33 is oifset toward the left on a vertical plane through the axis of the pin 34 sothat a pull upon the strap I1 toward the right-will tend to increase the grip of the dog upon the strapwhile movement of the strapI Aablyabore33lformedinthe gripping ser in the opposite direction withrespect to thegripping dog will release the dog from the strap. .This gripping dog 33V is normally held in strap-engaging position by a pin or plunger 31 which slid-- and`which`is pressed against a ange 3l on blockorhomingbymeanaofacoilspring mounted in the innen-'end of the bore,vas

shown particularly in Fig. 10. Assuming that the -seal joint I3 has not been formed and that the strap I1 has been passed around the package and the end portions Il and I1 thereof put in place beneath the grippingI dogs 23 and 33, re- '5 spectively, it will be apparent that relative movement -of the two blocks 23 and 30 toward each f other will draw the strap taut around the packagewith the ends thereof between the blocks in overlapping relation so that when the strap has 10 been brought to the required degree of tautnes's, thev seal may be applied to form the interlocking joint.

For the purpose of veifecting relative movement 1 of the blocks 20 and 3|.-a gear wheel`33 isar- 15 ranged to mesh permanently with the rack teeth 2|, as shown in Figs. 7 and 8, andl this gearv wheel is-rotatably mounted upon a bolt or pin 3l upon which there is pivoted an operating lever 4II having a spherical handle 4I at the outer end there- 2o of. As shown in Fig. 6, the bolt 38 engages apertures formed in bosses oriluhs which constitute `rparts of the side walls 33 and 30 of the block or housing 33, the bolt having an enlarged head 39at one end which is flattened at one side as 25 shown at 33" to engage the adjacent vertical shoulden `3Ih on the blofck to prevent rotation of the boit. At. the other end, the boitis provided with a threaded. portion engaged by a nut 4I. The gear wheel 33 is located in the chamber 30 381 between the side walls of the block or housing and it is embraced on opposite sides by the flanges 4IIb which are formed on the lower end of the op- .erating lever 4I and which are pivotally engaged b y the bolt or pin 39. The gearwheel 38 35 is rotated upon reciprocation of the lever 43 through the agency of a pawl 42 which is of cylindrical form as shown in Fig. 5, comprising a body portion 42n and a projecting end portion' 42bv of reduced diameter. 'Ijhe body portion' 42l 40 is journaled in apertures which are formed in the side flanges 43| of the operating lever and the part between the side angeS is milled of! to form a slot 42 having a at inner face 42d'and teeth .42 at its oppomte edges. 'I'he body portion 42* 45 projects beyond one side flange 4Il'J of the operatihg lever and this part is milled off to form another at face 42t which, when the lever 43 reaches a predetermined position in its angular move-f ment toward the right, as viewed in Fig. 1, engages a cam face 33* formed on the side wall 33I of the block 33 with the result that the pawl 42 is rotated to release from engagement with the teeth of the gear wheel il the tooth 42 or the pawl which has previously been in 'engagement 55 therewith, thus permitting the gear wheel to pass freely through the noteh'42c ofthe pawl: The pawl 42 is normally turned to a position wherein 'the tooth 42 engages the teeth of the ratchet wheel to cause rotation of the ratchet wheel, upon movement voi' the lever 43 toward the left as viewed in'FIg. 1, by the action of a coil.spring 44 which' is mounted around the reduced extremity 42 of the pawl with one end thereoiL passing through atransverse aperture 42 formed 65 in' this part of the pawl and with the other end' thereof bearing against a lug 4F 4which is pro-` vided on qneof the side flanges v48" ofthe yoperai'.- inrlever, as shown in Fig'. 4.. When the lever 43 is moved toward the 1eit, es viewed in Fig. i, the 7o' the pawl slides over the gear teeth so that the gear remains stationary while the lever is retracted to a-new starting position. During this4 reverse motion of the lever 40, the block 30 is held stationary with respect to the Arack bar 2| by oneor the'other of two detents 45 which are pivotally mounted upon a bolt or pin 46 extending through theside walls 3|)f and l3mi-of the block or housing, as shown in Figs. v6 o and 8. l.This bolt 46 has an enlarged head 4|iEL at one end lwhich overlies the side wall 3|!I of the y housing and 'vvhichisy preferably set into-a cir- A cular recess in the housing. At the other end,

the pin or bolt is threaded for-engagement by a 5 nut 4 1. The detents 45 are'provided with teeth 45 which are adapted to enter the recess, be- "tween the rack teeth 2| and these teeth 4 5a oi' the detents are oifset from each other longitudinally-of the rack bar, as shown in Fig.'8, so that they engage alternate spaces along the rack bar, one detent resting upon the top of onel toot when 'the other detent is engaging a recess' tween that tooth and the next adjacent tooth. These detents are, normally forced into engagement with the rack bar teeth by a pair of coil springs 48 which engage sockets 45" formed in the detents at one end and whic vhave their other ends arranged to contact wi an overhanging ilangefilk formed on the e wall .of the .30 block 30. y These detents are provide with arms bar'except for such resistance as may be provided by the resistance of the gripping dog 33 with the strap I1 if the gripping .dog is then in engagement with the'strap. The flange -3|lk of the block or housing is provided with a notch '301 which is adapted to receive the lower edge ci the operating lever 40 when itis in vits lowermost right'- hand position, as shown'vin Fig. 9. The extent to which the block may move toward the right 50. along thelrack bar 2|, asviewed in Fig. 1, is

limited by a pinor stop member 49 extending upwardly from .the'rack bar adjacent the righthand end thereof, as shown in Fig; l, and to facilitate the handling of the device in placing it ,-5 upon or removing it .from a package. this'end of 'the rack bar is provided with a mushroom-shape handle 5|) secured to the rack bar in an inclined -position by means of a screw 5|.

For the purpose of causing the automatic o release of the gripping dog 33 from the strap |1 after the strap has been drawn taut and the joint I8 formed, the, strap stretching device is provided with means for moving the gripping dog from the grippingvposition shown in Fig. 1 when C5 the lever 40 has been removed to the extreme right-hand position shown in Fig.'9 to release the detenta 45 from the rack bar.

is mounted a' coil spring 52r of greater strength by'a spherical ball 53 which' is adapted to press againstY an upright shoulder, 33 d formed'on the 75 gripping ldog 33, as shown in Fig. 10, and at its block or housing 3D to move freely along the rack The block 30 is .provided with an inclined passage, 30m in which other end, the spring 52 bears against another spherical ball 54 which is adapted to be engaged by the iace`of a cam' 55 formed on the adjacent side ange '40" of the operating lever -4|i.Y The cam 55 occupies a recess 30 formed in the side 5 lwall illI of the block or housing 30 and when the operating lever reaches the .position shown` by dotted lines in Fig. 9, the tam 55 vengages the ball 54 Aand moves it downwardly in the passage 3|)m with the result that the spring 52 is compressedand-the lower b all 53 is caused to exert a pressureupon the gripping dog 33 tending to turn it in a clockwise direction as viewed in Fig. 9. Owing to the resistance provided by the bite of the teeth of the serrated portion 33 oi the grip'- ping dog into thev metal of the strap Il, this Ipressure ofthe ball 53 upon the grippingv dog will not immediately release the gripping dog from the strap but when the operating lever 40 reaches its extreme right-hand position, shown byfull lines in Fig. 9, the pawls will be disengaged from the rack bar, thereby causing a slight' movement or 'jump of the block 30 due partly to the impact of the release `andpartly to the expansionv of the boundestrap which has .notbeen under tension in theregion between the blocks 20 and 3|l.y When this slight jump or movement of the block 30 takes place, the bite of the `teeth of the gripping d'og 33 in the middle of the strap will be released and the spring 52 will thenovercome' the spring 3lm and move the gripping dog 33about its-.pivot to the position shown in Fig. 9,v thereby automatically releasing the strap. At the same time, the operatormay actuate the handle 25 at the other end of the `device to release the gripping dog 23 so that the tool may then be movedsidewise to withdraw the anges 201" and 3|)cv fr om their positions beneathl the strap. In this way, the operation of the t'ool by a single operator is greatly facilitated and the release of the tool from the strap may be readily effectedA when vthe seal has been drawn taut and the joint formed. Although one form of the invention has been show nand described by way\ of illustration, it will be understood that it may beconstructed in various other forms coming within fthe scope of the appended claims.,.j A

I claim: f v

1. The combination in a, strap stretching de'- 50 vice, of means for gripping opposite end portions oia strap, means for effecting relative movement o f said gripping means todrawsaid strap taut aroundna package or thelike, and means actuated by said last named means for releasing said strap from one of said gripping means. 2. vThe combination in a strap stretching device, of means for gripping the strap, means for moving said gripping meansA t'o tighten said strap around a package or the like,means for actuating said last named means, and means operated by said. actuating means for releasing tsaid gripping means from said strap.

3. The combination in a Vstrap stretching deviceyof means for drawing a strap taut around a .package and then relieving the tension thereon after the ends of the strap have been secured together, a gripping device for holding said strap while -it is being drawn taut, and means operative when said tension is relievedv for releasing said strap from said gripping device.

4. The combination in a strap stretching device, of a pair of relatively movable members each adapted to be secured to a strap, a. gripping device carried by one of said members for gripping 75 said strap, means for effecting relative move;

ment of said members for drawing said strap taut around a e, means for operating said last named means,'and meansactuated by said last Y named means'ior effecting the release oi' said strap fronrsaid gripping device.

5. The combination in a strap stretching device, of a pair of relatively movable members each adapted to be secured toastrap, a gripping device carried by `one of said members for gripping said strap, means 'for eiecting relative movement of said members for drawing said strap taut around a package, means for operating said last named means, and means actuated by Vsaid last named means for storing up energy to effect the release of said strap by said gripping device after said strap has been drawn taut. 6. The combination in a strap stretching device,` of a pair of relatively movable members, means for securing one end portion of a strap to 'one of saidmembers, a gripping device carried bythe other of said members forrgripping another portion of said strap,'means for effecting relative movement of said members to draw said strap taut around apackage or the like, vmeans for opermovement of said membersto draw said strap taut around a package or the like, means for operating said last named means, means tending to maintain said gripping device in engagement with said strap, and means adapted to' be actuated by said operating means when said strap has been drawn taut for overcoming saidlast named means to release said strap from said gripping device.

8. The combination in a strap stretching de- Ivice, oi a pair of relatively movable members,

means :or securing one end portion of a strap to one oi' said members', a. gripping device carried by the other oi said members for gripping another portion of said strap, meansfor effecting relative movement oi' said members to draw said strap taut arolmd a package or the like, means for operating said last named means, means inc a spring for normally maintainingsaid 'gripping device in engagement with said strap, and a second spring adapted when compressed 'to overcome.

said dist-named spring to release said strap from said gripping device, said last-named spring being adapted to be compressed by said operating means after said strap hasbeen drawn taut. l'

9. The combination in a strap stretching device, of a pair of relatively movable member-Seach adapted ,to be'secured vto one end portionr of a strap, a gripping device for securing one of said members to said strap, means including a reciprocataing handle for effecting relative movement of said members to draw said straptaut arounda package o rthelike, acam actuatedby said hanaoaicil dle, by saidcam for causing said gripping-device to release said strap upon a.V

.predetermined movement oisaid handle.

1o. The combination in a mp' stretching de# vice, of a pair of relatively movable members each A5 adapted to be secured to one end portion of4 a strap, a gripping devicerfor securing one of said members to said strap, means including a reciprocating handle for eiecting relative movement oi said members to draw said strap taut aroimd a. packager or the like, a c am actuated` by said' handle, a. spring adapted to be compressed by a predetermined movement of said cam, .and means actuated by said 'spring for releasing said' gripping device from said strap.

. 15 11. The combination in a strap stretching device, of a pair of relatively movable members each adapted to be secured to one end portion of a strap, -a gripping device for securing vone of said members to said strap, means including a reciprocating handle for eiiecting relative move' ment ci' said members to draw said strap taut around a package or the like, a cam actuated by said handle, a spring adapted to be compressed by a predetermined movement oi said cam, means actuated by said spring for releasingsaid grippingdevice from said strap, and a second spring of lesser strength than said ilrst named spring engaging. said gripping device and tending to maintain said gripping device in engagement with said strap, said gripping device having a serrated gripping suurface adapted to engage said strap.

12. The combination in a strap stretching de vice, of a pair of relatively movable members each adapted to be secured to a strap passed around a package or the like, said members being adapted byrelative movement toward each other to draw said strap taut with its ends -overlapping in the g region between said members, a pair of gripping devices for securing said Astrap to said 4o members, a spring engaging o'ne'of said members and one of said gripping devices for maintaining that gripping device normally in engagement with Vsaid strap, said lastnamed member having a passage therein adjacent said last mentioned gripping device, a spring mounted in said passage, means comprising aY reciprocating lever for eiecting relative movement of saidmembers, and means actuated by said lever when it reaches a predetermined position for compressing said 5 -1ast named spring, said last mentioned gripping device having a serrated gripping surface.

13. The combination in a strap stretching device, of a pair of relatively movable 'members a strap passed around a package, .a gripping device for 'securing one of said members to said strap, means comprising a rack bar and a meshing gear for efiectingrelative movement ofi said fmembers; means including a reciprocating lever for rotating said gear, a detent for normally holding said gear` against reverse rotation, means including a spring adapted when compressed torelease said gripping device from said stra-p, and

leach adapted to besecured to one end portion of means actuated -upon a predetermined movement of saidJlever for releasing said gear from said detent and compressing said spring.

' WILLIAM C. CHILDRESS. 

